The State Scientific Center of the Russian Federation of NGOs TSNIITMASH the first time in Russia the technology in automatic TIG narrow gap and cuts to the main circulation pipeline (MTC) Du850.
Fct VVER serves for conveying water of the 1st loop reactor from the steam generator. Pipes for the pipeline thickness of 65mm and an outer diameter of 990mm are made of stainless steel pearlite 10GN2MFA clad with stainless steel inside. For welding steel 10GN2MFA as filler wire is used in a specially designed NPO TSNIITMASH welding wire, allowing reliably exclude the formation of porosity. As explained by the head of the laboratory for arc welding and repair of welded structures Viacheslav Hodakov hitherto welding MTC carried by hand. The technology developed in narrow welding provides a significant increase in productivity, which is very important because of the large volume of construction works. To improve performance, applied technology "hot wire", that is additive is fed preheated. According to the developed welding technology made three full-scale models using welding machines "Polisud" (France) and "ARKmashins" (USA). Welding was carried out with pre-and concomitant heating. After welding, heat treatment was carried out at a temperature of 640 +10-30 exposure? C. The results of non-destructive testing and determining the mechanical properties, made in the amount of validation tests, the results showed compliance with the requirements of the design and technological documentation.